HomeMy WebLinkAboutRUDOLPH FARMS INFRASTRUCTURE PROJECT - FDP220010 - DOCUMENT MARKUPS - ROUND 3 - DRAINAGE REPORT
NORTHERNENGINEERING.COM | 970.221.4158 FINAL DRAINAGE REPORT: RUDOLPH FARM
FORT COLLINS | GREELEY 2 | 14
B. DESCRIPTION OF PROPERTY
Rudolph Farm is approximately 119.09 net acres, including a portion of the north side of Prospect
Road and the area associated with the TRIC and Lake Canal.
Rudolph Farm is proposing developing twelve (12) pad ready lots. Therefore, all detention,
standard water quality, LID, and all associated storm water infrastructure will be installed with
this package. The project will consist of two local roads and one major road. However, Lot 7 will
not be getting developed with this project because the site layout his highly unknown at the time
of this report.
The site is currently an undeveloped parcel with an existing groundcover consisting of short
grasses. The existing on-site runoff generally drains from the northeast to the southwest across
flat grades (e.g., <1.00%). The north half of the site drains into the TRIC, the southwest portion
sheet flows to an existing 36” RCP that drains toward Boxelder Creek, and the southeast portion
of the site sheet flows into Lake Canal.
According to the United States Department of Agriculture (USDA) Natural Resources
Conservation Services (NRCS) Soil Survey classifies the site as primarily Garret loam (Hydrologic
Soil Group B) and Fort Collins loam (Hydrological Soil Group C).
The TRIC and Lake Canal are the only major drainageways within or adjacent to the project site.
The only modifications to these channels that the Rudolph Farm development is proposing are
installing box culverts underneath the proposed road crossings.
Groundwater has not been evaluated on this site but will be as part of additional geological
testing. It should be noted that other sites in the area have relatively shallow groundwater (5’-10’
deep), and we would expect to see similar conditions on this site as well.
C. FLOODPLAIN
The far northwest corner of the site is located within the existing Boxelder Creek Flood fringe,
floodway, and erosion buffer zone. The southeast and southwest portions of the site are in an
area of minimal flood hazard (Zone X). A copy of the FEMA Firmette (Map Numbers 08069CO984H
and 08069C1003G and effective date of May 2, 2012) is provided in Appendix E.
The far northwest corner of the site is also located in a city high-risk floodway as well as a city
high-risk 100-year floodplain. A floodplain map from the City of Fort Collins GIS system is
provided in Appendix E.
A LOMR was approved by FEMA dated February 21, 2019 (Case No. 17-08-1354P), and these
improvements have removed much of this property from the flood fringe and floodway. Most of
the development will avoid the effective floodplain/floodway limits per the LOMR revisions.